Actually as an old hand (been in the game since the late 80's) the proportion of women I saw has decreased from when I first started and has only turned around in the last five or so years.

Admittedly this is mainly in a corporate environment, but most of the women I started with tended not to come back when they started their family. I think with more family friendly hours and policies such as remote and flex working this may also change.

To say that "they are only doing it for the cash" is unlikely, as from what I have seen that drive tends to run in men more so than women. cf: all the "web developers" in the first tech boom who did not know shit from clay and vanished as quickly as they came in the bust.